oil in mower

[mmmkay777]

Hi, I have an old mower. I was wondering if I need to top up the oil in the gear box?

This is a picture of the gearbox:

https://goo.gl/photos/wY94Fmge2DxjDJGb7

The nut at the top comes off and I can see the oil is about half full. In the manual it says 'check every 30 hours and fill as necessary' so do I fill it to the top ?

Also it says sae ep90 - can I use sae 80 in it?

Thanks

 

[Mudball]

I would think that your manual should show a diagram as to the location of the fill/level plug which is normally located somewhere on the side of the gearbox. You would remove the side plug and fill from the top until it starts to run out then tighten both plugs back.
80W should be fine but I would prefer 90W.
Hope this helps.

 

[mmmkay777]

Hi there doesn't seem to be another plug. Only the one on the top, none on the sides, the two other sides look like the one in the picture. Is it possible to overfill it?? Thanks

 

[D2Cat]

Then just fill it just to where you can see about 1/2 of the output shaft. Or make a dipstick out of a wire or something and guess where the fluid level is if you can't see. Make sure there is a breather opening somewhere (like on the fill plug) so fluid doesn't expand and cause problems.

 

[mmmkay777]

Thanks for the reply. So the oil is about at that point so looks ok. Can't find a breather opening anywhere. This mower is about 35 years old I think. Should I drill a tiny hole in the top??

Thanks

 

[Mudball]

I would not drill a hole.
Is there a plug underneath on the bottom of the gearbox unit ?
Is there a model, name, etc... on the unit anywhere or in the manual ?